function objetoAjax(){
    var xmlhttp=false;
    try {
        xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
    }
    catch (e){
        try {
            xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
        }
        catch (E) {
            xmlhttp = false;
        }
    }
    if (!xmlhttp && typeof XMLHttpRequest!='undefined') {
        xmlhttp = new XMLHttpRequest();
    }
    return xmlhttp;
}
function goToAjax(container,page,parameters){
    var _container=window.document.getElementById(container);
    objAjax=objetoAjax();
    objAjax.open("POST",page,true);
    objAjax.onreadystatechange=function(){
        if(objAjax.readyState==4){
            _container.innerHTML=objAjax.responseText;

        }
    }    
    objAjax.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
    objAjax.send(parameters);
}